12666009 has 4 divisors (see below), whose sum is σ = 16888016. Its totient is φ = 8444004.

The previous prime is 12665987. The next prime is 12666019. The reversal of 12666009 is 90066621.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 12666009 - 2¹³ = 12657817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12666019) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2110999 + ... + 2111004.

It is an arithmetic number, because the mean of its divisors is an integer number (4222004).

Almost surely, 2^12666009 is an apocalyptic number.

It is an amenable number.

12666009 is a deficient number, since it is larger than the sum of its proper divisors (4222007).

12666009 is an equidigital number, since it uses as much as digits as its factorization.

12666009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4222006.

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 12666009 is about 3558.9336886208. The cubic root of 12666009 is about 233.1023207938.

The spelling of 12666009 in words is "twelve million, six hundred sixty-six thousand, nine".